Ice nucleation in a microfluidic chip, part 2
Metastable fluids, such as supercooled water, can be difficult to produce and maintain in a metastable state using large-scale containers. We produced supercooled water as cold as is possible: approximately -37 degrees Celsius in our system (further cooling is impossible due to the homogenous nucleation of ice).We used droplet microfluidics to produce special containers for supercooled water: water is contained in small droplets ~100 microns in diameter that are surrounded by a liquid container – a moving stream of liquid fluorocarbon.
This movie shows how drops of water freeze after the homogenous nucleation of ice. Such freezing is a two-stage process: (1) crystals of ice grow rapidly until the drop becomes a mixture of ice and water at a temperature of 0 degrees Celsius, then (2) the ice-water mixture freezes completely, at a slower pace, being cooled by the carrier fluid which has a temperature around -40 degrees Celsius.
Last updated on November 17, 2011
Ice nucleation in a microfluidic chip, part 1
Metastable fluids, such as supercooled water, can be difficult to produce and maintain in a metastable state using large-scale containers. We produced supercooled water as cold as is possible: approximately -37 degrees Celsius in our system (further cooling is impossible due to the homogenous nucleation of ice). We used droplet microfluidics to produce special containers for supercooled water: water is contained in small droplets ~100 microns in diameter that are surrounded by a liquid container – a moving stream of liquid fluorocarbon.
This movie shows how we produce drops of supercooled water on a microfluidic chip, continuously cooling water from room temperature until it freezes due to homogeneous nucleation at temperatures close to -40 degrees Celsius
Last updated on November 17, 2011